So far, out of the ones I can see, (I'm still going through FF8) FF7 wise, the ones that seem most relaxing are:
The Prelude (As Expected) *
Anxious Heart
Tifa's Theme*
Flowers Blooming in the Church.*
Honey Bee Manor
Who Are You
Infiltrating Shinra Tower
Red XIII's Theme
Holding My Thoughts In My Head,
FFVII Main Theme,
Ahead On Our Way,*
On That Day 5 Years Ago,
Farm Boy,
Waltz De Chocobo,*
Chasing The Black Caped Man,*
Trail Of Blood,
Costa Del Sol,
Mark Of The Traitor,
Mining Town,
Cait Sith's Theme,
Sandy Badlands,
Life Stream,*
Cosmo Canyon,
Great Warrior,*
Decendent of Shinobi,*
The Nightmares Beginning (My 3rd Fave Song from FF7)*
Stolen Materia,
Interupted By Fireworks (My Fave Song from FF7)*
You Can Hear The Cry Of The Planet,*
Aeris's Theme (My 2nd Fave Song From FF7)*
Buried In The Snow,
The Great Northern Cave.
Reunion*
A Secret Sleeping In The Deep Sea,*
Off The Edge Of Dispair,*
On The Other Side Of The Mountain,*
Sending A Dream Into The Universe,
If You Open Your Heart.*
These are basically the songs that are relaxing for FF7 the one's with *'s beside them are the most relaxing.
Updated :
This is the FF8 list of songs I found relaxing. Again, the ones that are the most relaxing will be indicated with a *.
Balamb Garden,*
Blue Fields,
Find Your Way,
The Loser,
Breezy,*
Tell Me,*
Julia,*
Roses & Wine,*
Junction,*
My Mind,*
Succession Of Witches (Creepy, but relaxing too :P)
Fragments Of Memories,*
Ami,*
Drifting,
Fishermans Horizon,*
Where I Belong,
Love Grows,
The Salt Flats,*
Trust Me,*
Eyes on Me (With Vocal)*
Truth,
Compression Of Time,*
The Successor.*
There you goenjoy.